Clutch



Jan. 8, -.1"9-35.'

F. s. KINGSTON T 1,987,194- I CLUTCH Filed June 4, .1932 s Shet-s-Sheet1 INVENTOR 5 Frederick ,S, Kir yston ATTORNEYS Jan.8,1935.

; s. KINGSTON 1,987,194 vcLuTcH ,Filed Ju e 4, 1932] 5 Sheets-Sheet sINVENTOR Frc dari/ck S. Kingston BY Eva/M 8.

ATTQRNEYS I Patented Jan. 8.193s L I Q 1 9 7 194 UNITED STATES PATENTOFFICE CLUTCH- K Frederick S. Kingston, Warren, Ohio, assignor, by

- mesne assignments, to GeneralMotors Corporatlon, Detroit, Mich., acorporation of Delaware Application une 4, 1932, Serial No. 615,391

5 Claims. (Cl. 192-86) Thisinventio'n relates to 1140171011 clutches ofFig. '1 is a section taken on the line indicated the type in which adriving, connection is estab- "at 7-7 in Fig. 6; t lished byengagementof axially separable clutch Fig. 8 is a fragmentary sectionthrough a elements provided with conical engaging surfaces, slightlymodified hub member with the engaging" 5 one external and the otherinternal. f ring shown in Figs. 6 and '7 mounted thereon; 5

The clutch of the present invention is of quite Fig. '9 is a sectionalview of the hub member general application but it is particularlysuitable with the engaging and'retaining rings removed;

- for use in electric motors to provide a releasable Fig. 10 shows amodified form of clutch in axial driving connection between the armatureof the section; 10 motor and the motor shaft.

The present invention has for an object to proat 11-11 in Fig. 10; Ivide a clutch in which the interengaging clutch" Fig. 12 is an axialsection showing a further elements have an effective frictional driving,enmodification of the expans'ible clutch element; gagement in which arelatively light pressure on Fig. 13 is a section taken on vthe lineindicated 15 the movable clutch element is sumcient to mainat 13-'-13 inFig. 12.

tain the driving engagement, and in which only In the accompanyingdrawings the clutch of a relatively smallforce is required to disengagethe present invention is illustrated as applied to the clutch element.an electric motor which is providedwith the usual A further object ofthe invention is to provide housing 1 in which the motor shaft 2 iscentrally an expansible internal clutchelement which is journalled. Themotor has an armature 3 which 20 provided with means for exertinga'positive radial is rotatably mounted upon the shaft 2 and held upp hron e expansible 8 8 8 PO against axial movement on the shaft. ti nthereof while in clut hing engagement, and A clutch element 4 is fixedto one. end of the v relievinB the r l uppor ing thru t pr or toarmature sleeve and the face of this clutch eleaxial disengagingmovement of the clutch element is recessed to prom e an internal conical25 ments. engaging face 5 of relatively small angle to ob- It is furtherthe object of the invention to obtain positive driving engagementbetween the vtain the vantageous results above referred to clutchmembers. The movable element of the in a clutch which has few p t whichi of imple clutch comprises a hub member 6 splined on the and ruggedconstruction and which can be manushaft'2 and movable axially toward andaway so f atured a a w st. from the clutch element 4, the hub member 6With the above and other objects in view' the having mounted thereon vaperipheral engaging invention may be said to comprise the clutch as ring'1 which is connected to the hub for rotation llust in the mpanyin d awis he eintherewith but which is yieldingly contractible .Fig. 11 is asection taken on the line indicated 10 v after described andparticularly set forth in the radially and provided with an externalconical 35 appe ded i together w h such vari tions face for engagementwith the internal conical and modifications thereof swfl be pp tosurface '5 of the clutch element 4 which has a one skilled in the art'towhich the invention aptaper corresponding to that of the internalconipertains. cal surface 5, a band of friction material 8 9 1118 40Reference should be had to the mp nyin secured 'to the periphery of thering 7. The in,- 40 drawing f i K .1 Of this p fi t o in terengagingconical faces of the clutch element which: 4 and ring '1 are tapered ata relatively small an-- Fig. 1 is a sectional elevation showing theclutch gle and the .hub member 6 and ring"! have interpp to an electricmotor; engaging conical faces 9 and 10 which taper in Fig. 2 isanaxialsection through the clutch the same direction as the conicalsurface 5 but 45- showing' the clutch elements disengaged at a greaterangle for ease in separating the clutch Y Fig. 3 is a section taken onthe line indicatedat elements. Relative rotation between the hub 3-3 inFig. 2; member 6 and ring '1 is prevented by means of" Fig. 4 is a sideelevation showing the parts of radial lugs 11 on the hub 6 which engagein the clutch separated; I recesses on the interior of the ring. Thering- '1 so Fig. 5 is a front elevation of the expansibie is atransversely split ring, and the ring has one engaging ring. viewed asindicated 'by the line of its lug receiving recesses 12 located at thesplit 5-5 in Fig. 4; j to locate one of the driving lugs between thesep-., Fig. 5 is a front elevation of a modified formof arable ends ofthe ring and one or more lug reas en a ri I ceiving recesses 13 areprovided in portions of u on the exterior of. the ring '30 the ring issplit of .the ring at a ported against contraction by while the clutchmembers ward' movement of the hub formed to provide sufllcient clearancebetween the lugs and recesses to permit the ring to expand or contractfreely intermediate its ends. By 10- cating a lug engaging recess at thepoint where andspacing the other recesses considerable distance from thesplit the ends of the ring are free to spread apart as the ringisexpanded and'binding between the ring and driving lugs is avoided.

The ring 7 is mountedfor axial movement on the hub '6 so that the ringmay be rigidly supthe conical face 9 of the hub when the hub member is.pressed toward theclutch element 4. "Pressure on the hub member 6 tendsto force the conical portion 9 thereof further into the ring and exertsan outward radial pressure 'on the ring which tends to expand the ring,to a larger diameter and thereby provides a relatively rigid supportfor, the ring arein driving engagement. The ring 7 maybe normally heldagainst the conical portion 9 of the hub member by means of. a spring 14which is interposed between an internal shoulder on the plate 15attached to the member 6 When the hub member 6 is moved toward theclutch element 4 the friction band 8 7 is brought into engagement withthe internal conical surface 5 impeding further axial movement,whereupon the conical portion 9 of the hub member 6 will eflectivelysupport the ring 7 against contraction and also apply direct radialthrust against the inter, nal engaging face 5 of the clutchelement 4.

When the hub member6 is moved in the opposite direction, the conicalportion 9 moves outwardly within the internal conical face 10 of the.

ring thereby removing the radial support for the ring and permitting thering to contract somewhat due to its resiliency, thereby relieving itfrom engagement with the clutch element 4. The

relatively great angular taper of the conical supporting face 9 of thehub member 6 permits withdrawal of-the' hub member by a minimum forceand insures against sticking of the clutch eledriving contact withltheinterior of the clutch element 4 largely by the radial support providedby the engagement of the conical faces 9 and 10 of thehub and ring, thetaper of theclutch faces in driving the movable, clutch element.Furthermore, the relatively small angle of taper of the internal andexternal engaging faces of the clutch elements enablesthe clutchelementsto be held in tight driving engagement by a relatively light axialpressure applied to the movable clutch element.

The relatively greatangle of taper-of the supporting face 9 of the hubmember-permits the release of the hub from the engaging ring withminimum of resistance and contract slightly because it ported internallywhereby the enga ing ring is readily freed from clutch element 4 uponoutlittle force is required to elements.

- face.

ring and a retaining. inner end' of the hub member and very disengagethe clutch In the electric motor installation herein illustrated. themovable clutch element is normally tween the outer face of the hubmember 6 and a collar 17 keyed to the shaft 2. i v By-reason of the factthat the supporting conical surface 9 has a greater angle of taper thanthe internal conical surface 5, the compression '5 of the wedge shapedring 7 between the conical surfaces 5 and 9 due to the thrust .of thespring 16 has a component tending to'cause the ring to move forwardly onits conical supporting sur- The eontractile thrust of the, ring 7 itself10 due to its resilience also has a component tending to move thering'forwardly on the surface 9. The spring 14 must, therefore, ,besuillciently still? I to resist these axial thrusts and prevent the ring7 fromcreeping forwardly with respect to the 15 6 during operation.Since the spring 16 applies the force which compresses the wedge shapedring 7 between the surfaces 5and 9 and which expands the ring 7, itwillbe apparent that the strength of the spring 14 need not be as great'asthespring 16 but should be greater than the components of the appliedthrust tending to cause thering 7 to slide forwardly on the conicalsurface 9. l 1 As herein shown, the clutch is providedwith 26 anelectro-magnetic actuating means for moving the hub member 6outwardly inoppositionjto the spring 16, the hub having attached thereto an annulararmature ring 18 carried by radially projecting arms. 19 and positionedin registry with an annular recess 20 formed in the housingwfall, anelectro-magnet .21 being mounted in the bottom of the recess 20whichwhen energized draws the armature "18 into the recess. 'l'heelectromagnet or other clutch releasing means must 85 be capable of exertingapull on the hub member 6 sumcient to compress the spring 16and'toovertract to a smallerdiameter there will'be very littlefrictional resistance to'withdraw'al ofthe ring from the interior of theclutch element 4 and the electro-magnet 21, which is're'quired to exertonly a light pull. my be operated with a relatively small current or mayhave relatively few turns.

the space between the flanges 23 and 24 and may of .any convenient form.'As shown inFig; 8, the hub member 6 may be provided with driv-' inglugs27 having exterior edges parallel with the the axis of the hub,

- tractile split ring 28 mounted in a peripheral with an internallyconical frictionally held in inner end of the hub and is free the ring28 and the radial groove near the to float between arms 19.

In Figs. and 1l of the drawings there is shown a modification there isprovided a sliding clutch element 30 which has a peripheral flange 31provided with a conical outer face upon which is mounted acorrespondingly tapered metal band 32 which fits snugly upon the conicalouter face of the flange 31 and which istransversely split to permit itto expand and contract as it slides on'the flange 31. The band 32 is aflat conical band provided with a suitable clutch facing 33 forengagement clutch element 34. 1

The'flange 31 is provided at its edge with circumferentially spacednotches 35 and the band 32 is provided at its inner edge withcorrespondingly spaced apertures or notches 36. Spring arms 37 extendingradially from a sheet metal disc 38 rigidly secured to the hub of theclutch. element 30, extend through the notches 35 of the flange 3l=intothe notches or apertures 36 of the expansible band 32, being of a widthto slidably fit between the side walls of the notches 35. The springarms 3'? normally press the expansible band 32 toward the large end ofthe conical flange 31 and serve to normally hold the band into snugengagement with the 'flange. The spring arms 3'1 also provide drivinglugs for the band 32, the

30 is forced into engagement withthe clutch element 34 frictionalengagement of the facing 33 with the interior of the band 32 to ride upthe incline of the flange 31 and this movement automatically expands theband to a larger diameter. Upon reverse moveelement 30 the facing 33 isthe clutch element 34 while the flange 31 slides outwardly "within theband 32 allowing the resilient contractile band to .contract to asmaller diameter and free itself from the clutch element 34, there beingsufficient play between the outer ends of the arms 3'! and band 32, topermit expansion ment of the clutch notches equally spacedcircumferentially, one of the notches of the band being at thetransverse split so that the band 32 is free to expand and contract.

In order to retain the band 32 on'the flange the band from being forcedand limits the outward movement of the arms '37 in the notches.

' Since there is meta to metal contact between the band 32 and theconical exterior surface of the flange 31, the band will slide morereadily of the invention in which the clutch element 34 causes clutchwhich and from the first ment 34, so that continued outward pull willreadiiy free the band from the interior of the clutch element 34.

InFigs. 12 and 13, a slightly different construct ion is shown. In thismodification the splined clutch element 41 is provided with a conicalflange 42 which has circumferentially spaced notches 43 in the edgethereof. Mounted on the conical flange 42 there is a resilientlycontractile transversely split clutch band 44 formed of resilient sheetmetal which has a taper corresponding to the flange so that it lies flatupon the flange. The split ring 44 is provided at its inner edge withdownturned tongues 45 which engage in the notches 43 and provide drivinglugs holding the hand against circumferential movement on the flange 42.The tongues 45 are engaged by-spring arms 46 which radiate from a sheetmetal-disc 4'7 fixed to the hub ofthe clutch element and which press theband toward the larger end of the conical face of the flange 42."Outward movement of the spring arms 46 is limited by means of a stopdisc 48 secured" to the hub over the disc 47 and having its peripheraledge just within the edge of the flange 42 to provide a stop for thearms 46. The band 44 is provided with a. suitable facing the interior ofthe conical clutch element, the operation in this case beingsubstantially the same as that of the clutch shown in Figs. 10

and 11.

It will be apparent provides a very simple,

that the present invention compact and economical and which requires butlittle force to disengage it, and that due to a very effective drivingaction is obtained when applied to an electric motor, clutch elementsand the clutch actuating devices may be very light and of inexpensiveconstruction. 1

Furthermore, it is to be understood that the particular form of clutchshown and described, and the particular procedure set forth, arepresented for purposes of explanation and i1lus-.I tration andthatvarious modifications of clutch and procedure can parting 'from myinvention as pended claims.

What I claim is: 1. A friction clutch provided with a conical internalengaging surface, and member mounted for movement axially toward clutchelement, said hubjmemher having a conical portion tapering in the samedirection as said internal engaging surface but at a greater angle andhaving circumferentially. spaced radial integral projections, saidsecond clutch member having a resilient transversely split ring slidably mounted on of the hub member, said ring having axially extendingrecesses on the inner face thereof to receive said projections, one ofsaid recessesbeing' defined in the ap- 49 for engagement with requiresonly'a light engagin spring the effective wedging action Y m i. be madewithout de-' .1.

the conical portion Q 2.;A friction clutch having ber and a recess atthe split, said ring having an extemal conical surface tapered toconformto the taper, of. said internal engaging surface and an internalconical surface tapered to conform to the conical portionof the hubmember and a spring disposed concentric of the ub for restrainingseparation of the ring and hub at their conforming surfaces. a clutchelement provided with a conical internal engaging surface, a secondclutch element having a hub member mounted for movement axially towardand from thefirst clutch element, said hub member having a conicalportion tapering in the same direction as said internal engaging surfacebut at a greater angle and hav ng a radial projection, said second and aspring mounted on said hub member, said spring having one end seated onthe hub and its opposite end bearing against said ring and acting toyieldingly pressthe ring toward the conical portion of the hub member.

3. A friction clutch comprising a clutch ele- Yv ment having an internalconical engaging sursaidengaging surface but at a resilient expansiblering mounted on the hub for face which tapers hub mounted coaxialiy withsaid clutch element for rotation relative thereto and for axialmovements with'resp'ect thereto, said hub having a conical end greaterangle, a

to receive said radial projection, through the notches at a relatively.small angle, a-

portion tapering in the direction of rotation therewith and for axialmovement thereon, said ringhaving an external engaging surface'taperedtoconform to said internal engaging surface and an internal surfaceengaging the conical hub surface, means I hub in relative non-rotatingengagement, and a coupling the ring and spring acting on said hubmemberand enga ng the ring to press the ring into engaging relation with thehub' conicalsurface. v

4. A friction clutch having two relatively rotatable clutch elementsmounted coaxially for relative axialmovement into and out of clutchingengagement, one of said elements having a conical surface, thevother ofsaid ele- I internal engaging ments having a correspondingly taperedsurface and circumferentiallv spaced notches .in an end thereof, aresiliently contractile sheet metal band' fitting on said taperedsurface andhaving notches registering with notches of .thetapered clutchI element, and radially to thetapered clutch element and extending theband. e v

v 5. A friction clutch having two relatively rotatable clutch elementsmounted coaxially for relative axial movement into and out of clutchingengagement, one of said elements having aconical

